Electric hammer



L. Pmulm ELECTRIC HAMMER.

APPLICATION FILED DEC 5.1911.

Patented Sept. 12,1922.

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vvn 98 K g k n lvm a? WITNESSES L. PAULERO.

ELECTRIC HAMMER.

APPLICATION mu) DEC 5. mu.

m m m m o m W ng. v ww m r W W m M a mu m m w w m r m P QR H m w L. PAULERO.

- ELECTRlC HAMMER. APPu cAnon mm use s. 19H. 1,429,094; at nte S pt- 12, 1922. 3 SHEETS-SHEET 3.

m g um k KW Mil/EN ms L 00063 3901116 r0 ATTORNEYS WITNESSES and useful Improvement 7-7 of Figure 6.

Patented Sept. 12, 1922.

LOUIS IAULERO, or rs'rnnssuns, vmernm,

.ASSIGNOR T0 AMERICAN" ELECTRIC TOOL comm, mconrona'rnnor ITETERSBUBG, VIRGINIA, A conromrron or VIRGINIA.

ELEc'rarc iiimm.

, Application filed beccmber 5, 1917. Serial so. 205,563.

To all whom it may 001mm.-

Be it known that I, LOUIS PAoLEso, a citizen of the United 'States, and a resident of Petersbur in the 'county of Dinwiddie' irgima, have invented a new' in Electric Hamfollowing IS a specificaand State of mers, of which the tion. y My invention relates to an improvement in electric hammers, being more partieularly an improvement in themethod of cooling the coils andcooperating parts, and it con-I sists in the constructions,combmationgand arrangements herein described andclaimed. An object, of my invention isv to provide an electric hammer wherein a forced draft is maintained through" the hammer casing and around the coils and cooperating parts, during the time that the hammer is in "operation. 1, Another object of the invention is to provide an electric hammer, including a 'fan driven solely by the, reciprocating action of the plunger, thereby utilizing the back stroke of the plunger, the force oflwhich was heretofore expended uselessly on the cushioning spring. I

Another object of the invention lies in the novel construction of the trigger op erated switch, which includes a air 0 movable electrodes through the'me ium of which the circuits to the coils are 'simul-' taneously broken. 'i p 4 V Other objects and advantageswill appear in the followingspecification, reference being had in the accompanying drawings, in which: 'f' i Figure 1 is a central longitudinal section of the hammer.

Figure 2 is a detail enlarged section of the anvil and guide.

Figure 3 is .a perspective view of the anvil guide. I

Figure 4 is a cross section on the line, 44: of Figure 1.

Figure 5 is a detail section showing one of the electrical connections on the casing head.

Figure 6 is a detail section of the fan and driving mechanism therefor.

Figure 7 is a cross section on the line netic "material stream of Figure 8 is a' detail perspective viewof the spiral driving her, portions being disassembled,

Figure Sis a crosssection on the line 9-9 of Figurefi.

Fi res IO'and 11 are tress sections on the lines 10-10 and 11-911 of Figure 1.

Figure 12 is a detail'section of thes'witch. Fi'gure'ld isaplan' view thereof. Figure 14 is-an enlargeddetail section 01 a prortion of the swimmer- 1 i re 15 isa diagramjatic viewshowe fco 'n'ection' noid magnet circuit;

1' The essential features of the invention reside in the mannerl'of forcing acurrent of air'aro'nd'the solenoidma et and the plunger, and in the bon creating I y striking oftheliead of the s iral I vin bar, by the plungerlon thbac stroke, an

consequently rotating a fan" in connection bar. Portions of. in' 'Figt'ire l are' dis with the spiral the invention illustrate closed in my co-pendirgggaEplicatiQn filed July 22, 1915, Serial r '4l3 99, atented December '14, l920, No 1,362,349. e-

fo're proceeding with the description of the,

essential features of y the invention outlined 15 above, it is' thoughtadvisablef to describe the elements of t e invention disclosed in the c'o-pending application. I

Briefly then, a air ,of solenoid 'coilsjl and2 aredrsposed inside of the cas-' in'g'3 and wound upon a spool 4 of diamagsuch fior, instance, as brass. The coils l' and 2are energized alternately and act upon he alternate 'energization of of the spool; H I V these colls'is obtainedbyithe special form bf the switch in solethe fp lu'ngerfi which is th'us caused to reci rocate rapidly in the bore 6" ments that appear 'in' saidapplication, and i a furtherdescription otherthanthat given, is thought unnecessary; 4 4 I Proceeding now, with the description of the invention, the plunger 5 is provided with a plurality'of relatively deep grooves? formed parallel to the axis of the plunger. These grooves permit the passage of the air created in the bore6, past currents created by'the coils' ljand 2.

A ger "forward reciprocations 1 is carried by an anvil clud 11.

n anvil 8 is located in front of the plun- 5 and is 'struck by the p 7 "thereof. 1 The-anvil giiide' 9- "-whi'ch' ines the threaded nose 10 having a bore a The body portion of the anvil'niov'es in 10 a counter bore 12, and a collar. 13 on. the

anvi

:b a afry' i 'i rip 1 Thepcri'pheralsurfac of theanvil guide-1 11x9 is longitudin ally grooved at .15. The.

.zhim i eias 26 "the 'im'piict with 'a r des grootesis have rad ll 1 i. the sa of'the j'groove's 15 a l is normally foi ced ag'a'insttheannular shoulder formed at athe junction of the ial extensions in the 1 in nd .16 h is to fperrnit the gut-of air toflowvinto aspace.18 surlia mbengl of the ir ita t ng e ri ld n .'metal vvhich is is given aiquarfrom, whence it fan sicii' the frontendand a m th spi l,

. ini a es? 6 agenda-sin. .The head ass at throughoutflit s length and 1 includes it'ted to. the.head. 23.

head", 23 has also lag; 28 on -the and adacent to; the. sqimre'; s lemn The collar 28 in'a hbreQ2 9 of a housing 30, prevented :from turning therein by fineans ofrtlie engagement of a spline 31 in thecollar"28 ter bore 29.

' vertic l i h steem 2. n t coun- "relativ ly light' coil spring as resses 'a'd 23fforwardl until the ce lax lfider 34 surrounding opening .in -which gthe head .23. moves. other end of the, spring 33 rests on'the ,w'all o f.a,bore.35 i Qusing inwhich salsa located, a heavy coilspring f 36. abso 'by the blows attire,

intended to receive and thesh'ocks imparted to the head 23 plungerfi. 'Thefspring 1 36 rests against the annular shoulder 37 formed at the and is screwed .The 'head '23 u juncture of the bores29 and ing'BO a separate member into the casinghead38 at 39. pon being struck by the The hous plunger 5 will move hackwardly in the counter bore 29, compressing the spring 33 until the buffer spring 36 is reached, in the meantime ing giving apartial turn to the spiral drivbar 24. This partial turn is imparted lunger on the V The ru p '20 "foundry; the eggs; 1 and 2," f om. virhich it swaps t 9a e ..'e$m9 r r u "series (if p'rfb rauc s l9 to the fan 20 by means of 'ofpawls 39 which engage the ratchct teeth '40 in the hub 41 of the fan-20.

Each pawl 39 includes a relatively heavy one or a plurality cess 43 in the head 44 of the spiral driving 'bar.'- The'head-Mjoinsthe spiral driving barat the circular shank' 45. "It-will be observed that the circular shank 45 and the square portion of the spiral driving bar meet at a gr'oove46 into which the ends of pins 47 mounted in the circular projection of the casing head 38, project The pins 47 a'rc held in placebya-band or ring 49which fits over the circnlar projection 4:8 and. is ..held inplace by a scre'ivor'pin 50.

A spr ng'fil mounted in .a recess 52 in the ,plane continuation 5 3 of-the circular recess 43, forces the pawl 39 outwardly and into engagement with the ratchetteeth 40. It jvilLbe' observed. that'the pawl 39 depends sole1y on'the ;heavy =heel 42, for its main- }in theicircular recess 43, and that 1. eriv t r 'n i eefil y e o under simi- 1a;cn cun tances, is; omitted. Another featpgehesilmt egarrangement of the circular ..1.- ;e in the-Ihead.44:. This recess is lofc'a'ted well into the sbody'of the head and "jcons equently leaves alip 43 which acts as ,im ,abutmentf. for Ithe pawl 39. The outer surface of the pawl is struck on an arc of substantially the same 'radius as that of the -head 44,;so;that .thepawl will-beconfined wlthinthe periphery of the head when urged to doso against-the tension of the spring 51. P cap 5 4 'closes the end of the hub 41. :The head 44', has a pintle .55 which occupies "a' recess-5s in thecap 54. Ball bearings 57 t assist the-easy rotation of the 'head 44. The cap 5 besides providing an end bearing for the spiral driving bar24, also keeps the pawls 39' in their places, It will now be un- ';derstood;' that the partial rotation of the spiral driving bar 24. caused by the impact ofthe plunger 5 onthehead .23, causesthe an 20.10 rotate} through the engagement of .the pawls 39 1vith the ratchet teeth 40 on the hub 41. As'soon as the plunger 5 recedes from the head 23. the spring 33 expands; driving the head 23 to its'original position, and counter-rotating the spiral driving bar 24. The pawls 39 then merely drag back over the ratchet teeth 40 ready for another thrust, while the fan 20 continues to rotate under the influence of the momentum imparted thereto through the action just described.

A band 58 embraces the blades of the fan. The band moves closely to the wall of the chamber '21, and in a measure serves to direct the air current forwardly. Obviously, the band also braces and strengthens the fan.

The air from the fan 20 leaves the chamround heel 42 which rests in a circular reber 21 and enters the space 18, through a plurality of segmental openings 59 in the casing head 38. The openings 59 are formed between webs 60 upon each of which, a current plug 61 is mountedr The casing head 38 is screwed into the hammer head 22 as shown. The hammer head 22includes the externally threaded annular flange 62 which extends beyond the casing head 38.

The casing head 38 is pressed-tightly against the adjacent surface of a boss 4 of the spool 4' when the parts-are assembled.

so that the plug 61 will be in firm contact with the coacting socket 62 in the boss 4- The casing 3 and hammerhead 22 are clamped together by a s lit ring 63 which includes the partly threaded portion 64 and the annular flange 65. The flange 65 enages an annular rib 3 on the ,casing 3. 1 bolt 66 clamps the ends of the ring63 "together. The ring 63 is first partly tightened by means of the bolt 66, and then screwed on the threaded flange 62 until theflange 65 binds upon the rib 3, whereupon thebolt hammer. head ,22

cuits of the coils 1 and 2, is shown in Figure 15. The construction of the switch is best shown in Figures 12 to 14 inclusive, to which attention isdirected.

The switch comprises an insulating base 77 which is' secured in the chamber 78 of the and hidden-from view by the cover plate 79 The base 77 has front and rear, standards 80 and 81 which are preferably formel integrally. with the base. TWO pairs of, contacts 82 and 83 are mounted. upon the base; v The contacts 82 are secured on, top of the; standard 80 and Atop 66 is fully tightened, andthe casing3 is.

The medial portion of the s col 4 as an air chamber 69 which surroun the bore 6. A web 70 defines the limits ofthe air chamber. An air gap 71 is formed outside of; the web 70, and holes 72 ofler communication between the air chamber and the air .gap. The purpose of the air chamber, holes and air gap. is to permit the free circulationof the air around the plunger 5 and .the solenoid coils. 1

A tool 73 is fitted in a steel bushing 74 in the chuck 7 5 of the hammer. The easin 3 is screwed on the chuck 75, and the threa ed nose 10 of the anvil guide 9 is screwed into the chuck as shown. A striker pin 76 of the anvil 8 abuts the end of the tool73. Each forward impact of the plunger 5 is transmitted to the tool 73 through the anvil 8 and striker pin 76. The purpose of the spring 14 in the bore 11, is to receive the force of the blow of the plunger 5 when there is no tool in the chuck 75, andprevent damage to the chuck which would. otherwise receive the blow were it not 'for the spring 14. a

A novel form of switch is also embodied in this form of the invention. The position of the switch with relationship to the cirbythe means already descri include curved spring tips 82. The contacts 83 are bent 'to include a vertical por-. tion ,84 whichlies against the standard 81 and 'forms a bearing for ashaft 85. Other portions of the contacts 83 are bent over the of the standard 81 where the are secured, and bent ,tolie on the top ofl the base 83 where they terminate in spring tips 83 cooperatingtlwith the tips, 82. r

ThereQaretwo of the shafts 85,- but these as well as..t he associated gmechanism, being of thefsameconstruction, a description of but one will ,be given Each, shaft 85 is mounted near oneend of an electrode bridge 86 which is also made of insulating material and has a ,central pin 87 engageable by a trigger 88 through the medium of which the shafts andclectrode bridge are moved the spring 94 whichisconsiderably weaker than the spring 89, is to permit a certain latitude or freedom of motion of the shaft 85, afterjthe electrode 91 is thrust between the spri tips of the contacts 82 and 83, when sai spring tips press groove 92. g

Theiwires leading to the switch and the coils 1 and 2, are conducted through a passage 96 iirtbe handle 97 of the hammer head. Abushiii ,98 =insulates the wires from the inetaLo the'ha ndle. The operation of the devioeisas follows:

The coils 1 and 2 are energized alternately ed as being the subject;matter of a pending application, whereupon, the lunger 5 being alternately attracted, is made to reciprocate very rapidly in the bore 6 of the diamagnetic spool 4. The anvil'8 and the head 23 are thus alternately struck. The impacts on the anvil Bare transmitted to the tool 73. A portion of the shock is absorbed by the spring 14. The spring 14 will absorb all of the shock in the event that the hammer is into the annular.

a spiral driving bar partially rotatable upon movement of the head, a ian, and driving connections between said-bar and the fan for impartin' intermittent rotational impulsestothe an.

10. In an electric hannner,-a reciprocating plunger, a reciprocatory non-rotational head receiving alternate impacts of the plunger,

having an internal ratchet circumposed on the driving bar head, and pawls loosely mounted in said recesses and engageable with said ratchet.

12. In an electric hammer, a reciprocating plunger, a head receiving alternate impacts of the plunger, means permitting the reciprocation of said head and preventing rotation thereof, a driving bar partially rotatable upon reciprocation of the head, means preventing end-wise movement of the drivmg bar, a fan operated by the driving bar, and driving connections between said bar and the fan.

13. In an electric hammer, a casin head including a circular projection, a spira driving bar rotatable in said head and projection, the bar having a groove and square and circular portions on opposite sides of the groove, means carried by the circular projection partly entering the groove, and a band fitted over the projection to hold said means in place.

14. In an electric hammer, a driving bar comprising a portion non-circular in cross section partly twisted to form a spiral, and a circular portion, said portions meeting at an annular groove, a pawl head havin a semi-circular recess with an extending ip and plane portion, and a pintle in the center of said head.

15. In an electric hammer, a spiral housing having a bore and a counter bore leaving a shoulder at the juncture of the bores, a spiral drivin bar partly occupying said housing, a riving head movable in the counter bore and receiving the end of said bar, and a bufler spring absorbing the shock of the movement of said head and resting against the shoulder between said bores.

16. In an electric hammer, a spiral housin having a bore and a counter bore leavin a smulder at the juncture of the bores, sai counter bore having a longitudinal groove, a spiral driving bar partly occupying said housing, a driving head movable in the counter bore and receiving the end of said bar, a spline carried by said head and slidable in the groove, a buffer spring resting agai st said shoulder and absorbing the shock of th forward movement of said head, and; a

spring for returning said head to the initial position.

17. In an electric hammer, a spiral I sing including a borewith a counter b having a longitudinal groove, said bore 1 minating in a restricted opening, a drivi head including a body portion movable i said opening and having a. collar movabl i the counter bore, a spline carried by the 1. lar and occupying the groove, means f pressing said collar against the shoulder b tween the restricted opening and the count bore, and a. driving'bar including a spi l portion partly occupying one end of th driving head.

18. In an electric hammer, a spiral d i ing bar having a head with pawl rece including lips and spring recesses, a f having a hollow hub receiving said h d and provided with an internal ratchet i cumposed on the head, a pawl located i each recess including a wei hted heel tered below the edge of the 'p, a sprin i each spring recess pressin the pawl agai t the ratchet, and a cap 0 osing the holl hub and holding the glawls in place.

19. In an electric ammer, a casing, plunger, solenoid magnet coils for reci' eating the plunger, a fan, a spiral drivin bar operatively connected with the fan an including a driving head receiving alter t impacts of the plunger to rotate the fan, and a hammer head aflixed to the casing i cluding a chamber housing the fan, id chamber havin a screened air opening.

20. In an e ectric hammer, a groq d plun r, solenoid magnet coils surroundi the p unger, a hammer casing in cireumf entially spaced relationship to the coil fan, means for rotatin the fan upon alt natc reciproeations of t e plunger, to cr t a current of air through the circumferential space and the grooves of the plunger, d means located at the head of one of the il adjacent to the fan for dividing the i current.

21. In an electric hammer, a spool ha i circular segmental pyramidal pro'ection ,1; one end, a plun er reclprocatable m the b r of the spool an having longitudinal gro on the periphery, coils wound upon th spool, a casing in eircumferentially sp d relationship to the spool and coils, and a, f n including operating means actuated by th plunger, for directing a current of air t ward said projections, for causing the rent to flow into said space and through th grooves of the plunger.

22. In an electric hammer, a casing, an

fi dled hmmnel' howl having an air (humu medial portion and a bore, Said portion I it fun ruvoh 'nble 1n sunl chamber, a on inning all :In' chamber surroundlng the bore j iiead having openings admitting the air ith a perforated web and an air gap 60mt the casing, a Spool In the casing including munlou ting with said chamber through the 5 boss having openings coinciding with the perforations, and a, plunger reciprocatable: A

(-asing-l'iead openings, and a pyramidal pr0- in said bore, having longitudinal air grooves j tioniformed on vthe end of the spool and in constant COIDITlHl'llCfltlOIl with the an dis osed near said coincldlng OPBIUHgSfOI' chamber.

liv dingthe air current. 10 23 In an electric hammer, a spool having LOUIS PAULERO. 

